1. Field of the Invention
The present invention relates to an electro mechanical device to inject ozone into a dry cleaning machine which uses organic solvent such as perchloroethylene. More specifically, my invention is primarily intended to provide a user such as a dry cleaning employee a system to inject ozone in a closed loop into a dry cleaning machine to eliminate odors and gas such as perchloroethylene gas in a convenient, economical and environmentally safe way. The present invention can be utilized with an existing dry cleaning machine or can be utilized with the construction of a new dry cleaning machine. The present invention also relates to a method of injecting ozone into a dry cleaning machine after the solvent cycle to eliminate any residual perchloroethylene gases left in the wheel housing and to recirculate any residual perchloroethylene gas that has gravitated outside the wheel housing.
2. Description of the Prior Art
The utilization of ozone in the washing and dry cleaning business is well known. Ozone is a molecule consisting of three oxygen atoms which a triatomic allotrope of oxygen which consist of two oxygen atoms. When oxygen is passed through an electrical field, the electrical field breaks apart the oxygen molecules into free atoms. These singular oxygen atoms then bond to oxygen atoms to form ozone molecules.
When ozone comes in contact with odors, oxidation reoccurs, resulting in the elimination of the odors and the release of oxygen. As formed, ozone is a positively charged molecule which attracts to negatively charged molecules such as organic and hydrocarbon stains found in greases, fats and oils. When the ozone is injected into a cleaning solvent, it reacts chemically with the stains causing the stains to break up into smaller pieces. Further, ozone acts as a bactericide and is the strongest oxidant commercially available with results thousands of times faster than chlorine. Additionally, ozone eliminates odor causing bacteria by cell lysing where the ozone molecule molecularly ruptures the bacteria membrane destroying the bacteria in a matter of seconds. This process eliminates the bacteria and thus prevents any ozone resistant strains from forming. Chlorine on the other hand takes up to thirty to sixty minutes to eliminate the bacteria.
Accordingly, ozone is commonly used in the wash and dry clean industry as the ozone efficiently breaks down organic compounds resulting in less cleaning chemicals used in the cleaning operation. Thus, the use of ozone in the cleaning industry produces a number of significant environmental benefits and cost savings as less chemical results in less pollutants and less production costs. With the beneficial properties of ozone, however, come hazards. Ozone is highly toxic when directly exposed to humans. OSHA regulates that the maximum allowable limit for an eight hour period is 0.10 parts per million. Utilization of ozone in the cleaning industry typically results in off gases of the ozone in that all the ozone is not used and dispenses into the air. Ozone, fortunately, however is not a stable gas and breaks down into oxygen in about thirty minutes in open air.
In the dry cleaning industry, a solvent is used to clean the load of articles as opposed to a wash system. In a wash system, water is treated with a cleaning chemical which then in turn washes the load of articles such as clothing. Today, the common solvent presently used is perchloroethylene hereinafter referred as xe2x80x9cperc.xe2x80x9d Perc is an exceptionally effective solvent as it dissolves virtually all organic stains, including oils, greases, fats and waxes resulting in minimized need for pre-spotting and re-working. Perc penetrates fibers quickly and dissolves soils resulting in shorter cleaning cycles.
Perc is chemically and thermally stable under normal conditions of use but it does require proper handling and use. Exposure to continual and extremely high vapor concentrations can cause severe depression of mental functions, respiratory failure and even death. Further, prolonged and repeated contact will cause rough and dry skin leading to infection. Also, if swallowed, perc may cause serious liver effects and possibly death. Further, perc may be cancer causing. In fact, the State of California, under California Proposition 65 has listed perc as a chemical known to the state to cause cancer.
As such, steps need to be taken to reduce exposure to perc. In the dry cleaning operations, the door to the wheel housing should be closed at all times except when transferring a load of articles. When a wheel housing door is opened, residual perc gases gravitates to the floor as perc is heavier than air. Thus perc is not readily diluted in the air but exists in the room. Further, utilizing a closed loop system should be used to limit exposure as a closed loop does not expose the solvent to the air. After the dry clean step in most cycles, perc residue remains on the clothes as the deodorizing step does not terminate all perc. Thus, a customer will bring perc back to their home. Accordingly, public exposure should be minimized by cutting down on residual perc in cleaned garments.
In the present state of the art, a dry cleaning system and method does not exist to inject ozone directly into a wheel housing after the solvent cycle to reduce perc residue gas remaining on the load of articles. Further, in the present state of the art, a system does not exist to reduce off gases such as perc that travels outside the wheel housing when the door is opened. The state of the art is such that present dry cleaning equipment and methods utilize ozone to clean during the solvent cycle.
In U.S. Pat. No. 5,511,264 issued to Nishioka discloses a method for deodorizing and refreshing for dry cleaning. This invention uses a solvent such as perc in a dry cleaning apparatus having a cleaning bath, a solvent storage tank and a circulating pump. The components are interconnected so that the perc is pumped from the solvent storage tank by the circulating pump to be supplied to the cleaning bath through the path and the solvent is returned from the cleaning path to the solvent storage tank. In this method, an ozone generating device injects ozone directly into the solvent as fine bubbles. The ozone generating device injects ozone into the bottom of the solvent tank by using a diffuser where the diffuser spreads the ozone uniformly into the solvent. Thus, the load of articles is cleaned with ozonated solvent during the solvent cycle. After, the solvent cycle, the load of articles is dried and removed from the machine. The ozonated solvent is returned through filters to the solvent storage tank.
Limitations exist, however, with this system and method of deodorizing for dry cleaning. Although the ozonated solvent is filtered for reuse, the method still leaves perc residue on the load of articles as the perc is mixed with the solvent. Thus, the public has exposure of perc as it remains on clothes to be brought back. Further, the system and method leaves off gas ozone and perc gas residue inside the clean bath of the dry clean machine. Thus, when a door to the clean bath is opened, perc gas residue will gravitate near the floor surface exposing users in the room as the system and method does not draw this gas residue to an ozone generator to be recirculated.
U.S. Pat. 5,195,252 issued to Yamada discloses a method for dry cleaning as well as a method for recovery of solvent. In this method, an open system is used where outside air is brought into a treating drum of a dry cleaning machine. After the contents of the treating drum are treated with a solvent such as perc, the treating drum is stopped. An upper opening located in the treating drum is then opened. Simultaneously, a lower opening located at the bottom of the treating drum is slowly opened and exhausts the solvent into a treating tank. Thus, the solvent is replaced during this open cycle with the outside air.
This method, too, contains limitations. First, the system is an open system which is not recommended for perc use in the dry cleaning industry as perc may escape into the room. This open system exposes the perc gas residue to the environment without drawing it back for recirculation. Second, the system does not utilize ozone to terminate the perc gas. Accordingly, the open system leaves the perc gas residue on the articles that were sent through the deodorizing cycle.
U.S. Pat. No.""s 5,625,915, 5,806,120 and 5,960,501 disclose ozonated laundry systems. These systems are utilized with a water wash cycle as opposed to a dry clean cycle which utilizes solvent instead of water. Each of these systems injects ozone from an ozone generator directly into the wash cycle where the ozone diffuse into the water. Thus, the ozone is mixed with the wash cycle and drained out of the washing machine via either a recirculation circuit or to a drain. These systems do not address any reduction in ozone off gassing or other gas residue as the systems are utilized in a washing machine whereas the present invention injects ozone separately after the solvent cycle.
What is needed then is a means for eliminating perc gas residue remaining on the articles that have dry cleaned while further eliminating perc gas residue and ozone off gas remaining in the dry clean machine. Further, what is needed is a means for eliminating perc gas residue which gravitates toward a floor surface when the dry cleaning machine is opened.
It would become highly economical and beneficial for environmental issues and safety concerns to eliminate the residue of solvent gas remaining on articles that have been dry cleaned.
It would also become highly advantageous for environmental and health concerns to circulate and eliminate solvent gas residue which has gravitated outside the dry cleaning machine and exposed inside a room.
Accordingly, it is a principal object of my invention to provide a system and device to eliminate the residue of solvent gas remaining on articles that have been dry cleaned.
It is a further object of my invention to provide a system and method to circulate and eliminate the solvent gas residue which has been released upon opening the dry cleaning machine.
Other objects of my invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or apparent from, the following description and the accompanying drawing figures.
According to my present invention I have provided an ozone injector system for injecting ozone in a closed loop to a dry cleaning machine which comprises a dry cleaning machine having a wheel housing therein for receiving a load of articles to be cleaned. The wheel housing is threadably connected to a transfer line which injects solvent into the wheel housing from a solvent source means located nearby.
An ozone generator which is slideably positioned adjacent to the dry cleaning machine is provided. The ozone generator directly injects ozone into the wheel housing for eliminating odors and solvent gas residue such as perchloroethylene remaining inside the wheel housing. Perchloroethylene gas is the preferred solvent utilized in the dry cleaning industry. The ozone generator comprises an enclosure assembly which is supported at a substantial height above a floor surface allowing a circulation space for drawing perchloroethylene gas residue which has gravitated outside the wheel housing through an air filter. The air filter is positioned on the bottom of the enclosure assembly for filtering the air and perchloroethylene gas residue drawn up from the floor surface.
My invention further comprises an ozone injector assembly flexably positioned by a flex tube to inject ozone and solvent into the wheel housing from the ozone generator. The ozone injector assembly further comprises a solenoid ozone valve which is threadably connected to the flex tube for controlling the ozone flow into the wheel housing. The ozone injector assembly further comprises a solenoid solvent valve which is threadably connected to the transfer line for controlling solvent flow. The solenoid ozone valve and solenoid solvent valve are threadably connected to each other by a tee fixture which is threadably connected to the wheel housing by the transfer line for injecting solvent and ozone into the wheel housing. A gas sensor is located inside the wheel housing to monitor the amount of ozone and solvent.
A controller is utilized for electrically communicating with the ozone injector assembly for activating the solvent solenoid valve and the ozone solenoid valve for controlling the solvent flow and ozone flow. The controller automatically signals the ozone generator to vary the ozone depending on contamination of the load of articles. Further, a cooling fan is utilized where the cooling fan is fixably mounted on top of the dry cleaning machine. The cooling fan is connected to the wheel housing for translating air to the wheel housing for cooling the wheel housing where the cooling fan is electronically controlled by the controller.
I have also provided a method of using an ozone injection system to inject ozone in a closed loop to a dry cleaning machine and to draw residual gases off the dry cleaning machine, the method comprising multiple steps. The user selects a solvent selection on a controller from a plurality of solvent selections and initiates a solvent cycle corresponding to the solvent selection. The solvent cycle then injects solvent into a wheel housing. The user then terminates the solvent cycle corresponding to contamination of a load of articles to be dry cleaned and begins injecting ozone from the ozone generator. The ozone is injected by an ozone injector assembly directly into the wheel housing after the solvent cycle and the cooling cycle. Before ozone injection though, the controller transmits a solvent signal from the controller to close a solenoid solvent valve to stop solvent flow into the wheel housing while simultaneously transmits an ozone signal from the controller to open a solenoid ozone valve to inject ozone into the wheel housing. The user then can vary the ozone production from an ozone generator corresponding to the load of articles to be dry cleaned either automatically by the controller or manually by the user. The controller can determine an ozone level and a solvent gas level by the controller in the wheel housing and transmit a production signal from the controller to vary a gas sensor the ozone production from the ozone generator.
The controller then transmits a cool signal from the controller to a cooling motor to introduce air and to cool the wheel housing before the ozone is being injected. Upon completion of the cooling, the user then terminates the cooling motor and the ozone production. Next, the user opens a door of the wheel housing to unload the load of articles while allowing any heavier than air perchloroethylene gas residue to gravitate near a floor surface. The user then activates the ozone production to draw the perchloroethylene gas residue that has gravitated toward the floor surface into the ozone generator to recirculate the perchloroethylene residue gas. The controller closes the solenoid ozone valve to prevent any ozone or perchloroethylene gas residue to be injected. A fan of the ozone generator is then activated to circulate the fallen perchloroethylene gas residue after termination of the ozone production to further reduce perchloroethylene gas residue.